Proper grip and handling via good suspension geometry, proper diff, and proper tyres, will all make a bigger difference overall than less weight, IMO.

Sierras understeer too much and dont have enough steering self correction (lack of front camber and castor), have a diff so crap it may as well be an open one, and terrible rear suspension geometry (too much toe out and neg camber).

Sort that lot and the motor will be transformed IMO.